RNA interference (RNAi) is a gene silencing mechanism that is present in animals and plants and is triggered by double stranded RNA (dsRNA) or small interfering RNA (siRNA), depending on the organism. In the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), RNAi can be achieved by feeding rootworms dsRNA added to artificial diet or plant tissues tr...

High-fecundity organisms, such as Atlantic cod, can withstand substantial natural selection and the entailing genetic load of replacing alleles at a number of loci due to their excess reproductive capacity. High-fecundity organisms may reproduce by sweepstakes leading to highly skewed heavy-tailed offspring distribution. Under such reproduction the Kingman coalescent of binary mergers breaks do...

it has been hypothesized that the survival, development, fecundity and population of insects are affected significantly by high temperatures. the diamondback moth, plutella xylostell (l.) (lepidoptera: plutellidae), is a serious and economically important pest of cruciferous crops throughout the word. in this research, the adult longevity and fecundity of p. xylostella were studied in laborator...

Life-history traits are very sensitive to extreme environmental conditions, because resources that need to be invested in somatic maintenance cannot be invested in reproduction. Here we examined female life-history traits in the Mexican livebearing fish Poecilia mexicana from a variety of benign surface habitats, a creek with naturally occurring toxic hydrogen sulfide (H2S), a sulfidic cave, an...

Goat fecundity is important for agriculture and varies depending on the genetic background of the goat. Two excellent domestic breeds in China, the Jining Grey and Laiwu Black goats, have different fecundity and prolificacies. To explore the potential miRNAs that regulate the expression of the genes involved in these prolific differences and to potentially discover new miRNAs, we performed a ge...

Aphids are sap-feeding plant pests and harbor the endosymbiont Buchnera aphidicola, which is essential for their fecundity and survival. During plant penetration and feeding, aphids secrete saliva that contains proteins predicted to alter plant defenses and metabolism. Plants recognize microbe-associated molecular patterns and induce pattern-triggered immunity (PTI). No aphid-associated molecul...

We use population genetic methods to describe the expected population dynamics of the selfish-gene chromosomal factor, Medea (maternal-effect dominant embryonic arrest), recently discovered in flour beetles, genus Tribolium. In the absence of deleterious effects on gross fecundity, Medea factors spread to fixation for all degrees of maternal-effect lethality greater than zero and the rate of sp...

In many organisms, large offspring have improved fitness over small offspring, and thus their size is under strong selection. However, due to a trade-off between offspring size and number, females producing larger offspring necessarily must produce fewer unless the total amount of reproductive effort is unlimited. Because differential gene expression among environments may affect genetic covari...

Gene flow from transgenic crops allows novel traits to spread to sexually compatible weeds. Traits such as resistance to insects may enhance the fitness of weeds, but few studies have tested for these effects under natural field conditions. We created F 2 and F 3 crop-weed hybrid lineages of genetically engineered rice (Oryza sativa) using lines with two transgene constructs, cowpea trypsin inh...

Psychiatric disorders are disadvantageous behavioral phenotypes in humans. Accordingly, a recent epidemiological study has reported decreased fecundity in patients with psychiatric disorders, such as schizophrenia and autism spectrum disorders. Moreover, the fecundity of the relatives of these patients is not exceedingly higher compared to the fecundity of the relatives of normal subjects. Coll...